Submission #583666

#	Time	Username	Problem	Language	Result	Execution time	Memory
583666		Mystic03	Combo (IOI18_combo)	C++17	100 / 100	40 ms	536 KiB

combo

#include "combo.h"
#include <vector>
#include <algorithm>
#include <string>

using namespace std;
std::string guess_sequence(int N) {
	string s = "";
	vector<char> rem{ 'A', 'B', 'X', 'Y' };
	if (press("AB")) {
		if (press("A")) {
			s.push_back('A');
		}
		else s.push_back('B');
	}
	else {
		if (press("X")) {
			s.push_back('X');
		}
		else s.push_back('Y');
	}
	if (N == 1) return s;
	rem.erase(find(rem.begin(), rem.end(), s[0]));

	for (int i = 1; i < N - 1; i++) {
		int len = s.size();

		string check = s;
		check.push_back(rem[0]);
		check.push_back(rem[0]);

		check += s;
		check.push_back(rem[0]);
		check.push_back(rem[1]);

		check += s;
		check.push_back(rem[0]);
		check.push_back(rem[2]);

		check += s;
		check.push_back(rem[2]);

		int newLen = press(check);
		if (newLen == len + 2) s.push_back(rem[0]);
		else if (newLen == len + 1) s.push_back(rem[2]);
		else s.push_back(rem[1]);
	}
	string finalAns = s;
	finalAns.push_back(rem[0]);

	if (press(finalAns) > (int)s.length()) {
		return finalAns;
	}
	finalAns.pop_back();
	finalAns.push_back(rem[1]);
	if (press(finalAns) > (int)s.length()) {
		return finalAns;
	}
	finalAns.pop_back();
	finalAns.push_back(rem[2]);
	return finalAns;

}

• Subtask 1: 5 / 5
• Subtask 2: 95 / 95